[Cup dissociation after reduction of a dislocated hip hemiarthroplasty].
OBJECTIVE
Close reduction of a bipolar hemiarthroplasty dislocation may induce dissociation between the cup and the prosthetic ball head. This rare complication leads to reoperation.


METHODS
Two women 84 and 85 years' old suffering from femoral head fracture were treated by bipolar hemiarthroplasty through a postero-lateral approach. After the first post-operative month, a posterior dislocation has occurred. Close reduction, without anesthesia dislocated the intraprosthetic joint.


CONCLUSIONS
Dislocation rate is lower for bipolar hemiarthroplasty than for total hip arthroplasty. Reason for these two dislocation was supposed to be a "bottle-opener" effect's by locking the cup on to the posterior acetabular rim. Limb traction is responsible for intra-prosthetic iatrogenic dislocation.


CONCLUSIONS
Anesthesia should be considered as necessary for prosthesis bipolar hemiarthroplasties dislocation treatment. The authors have moved to a different implant and modified their surgical approach (antero lateral). These modifications were introduced in order to reduce the rate of hip dislocation and above all the event of intraprosthetic dislocation when close reduction was necessary.
Loubignac
F
F
Service de chirurgie orthopédique et réparatrice, Hôpital Renée Sabran, Presqu'5bile de Giens, Hyères.
Boissier
F
F
D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006617:Hip Dislocation / Q000209:etiology / Q000601:surgery*; D006801:Humans; D011379:Prognosis; D011475:Prosthesis Failure; D012086:Reoperation
Dissociation de la cupule au cours de la réduction d'une luxation de prothèse de hanche intermédiaire.